Heretofore there has been many patent applications relating to the self-inking stamp of this kind, e.g. those in which the stamp is formed of fixed characters, or of a rotary stamp using an endless rotary character belt. In such a self-inking stamp, the character arrangement block and the ink pad which are always contacted with each other must be kept in a separated condition when performing replacement of the character arrangement block, change of characters by rotating the endless rotary character belt, replacement of the ink pad or replenishment of ink. However it is difficult to perform these operations since it is impossible to keep a separated condition between the character arrangement block and the ink pad in such a self-inking stamp.
Improvements of these problems in the self-inking stamp have been disclosed in Japanese Laid-open Utility model Publication No. 54-134520 (1979) and U.S. Pats. Nos. 5,152,223, 5,727,467 and 5,850,787. In a self-inking stamp of this type, the character arrangement block and the ink pad are always contacted with each other by coil springs and the stamping of characters can be performed simultaneously with 180° reversing of the main body of stamp containing the character arrangement block and the locked condition can be obtained when the main body of stamp is reversed by 180°.
Japanese Laid-open Utility model Publication No. 54-134520 (1979) and U.S. Pat. No. 5,152,223 disclose a self-inking stamp in which the locked condition can be achieved by inserting a stopper member into an opening formed by alignment of an opening formed on an outer frame member and an opening formed on an underlying part when the outer frame member is pressed downward against a force of the elastic member and the main body of stamp is reversed by 180°.
U.S. Pat. No. 5,727,467 discloses a self-inking stamp which is locked by engaging a tongue portion formed on an outer frame member with a recess formed on an inner frame member when the outer frame member is pushed downward against an elastic member.
U.S. Pats. Nos. 5,850,787 and 7,069,852 disclose a self-inking stamp which is locked by engaging an engaging push button formed on an outer frame member with a notch formed on an inner frame member when the outer frame member is pushed downward against an elastic member.
As described above the self-inking stamps of this kind are those structured so that operations such as replacement of the character arrangement block, change of the character arrangement block by rotating the endless rotary character belt, replacement of the ink pad and replenishment of ink can be performed in the locked condition by reversing the main body of stamp by 180°.